Contacts

My mobile phone automatically saves each phone number to the contact book after any call, as long as the number isn't already saved. Determine how many unique entries are in the contact book, given a list of phone numbers from all N mobile connections.

Input

The first line contains the integer N ( 1 ≤ N ≤ $10^5$ ), representing the number of mobile connections. The second line contains N phone numbers, each a nine-digit natural number.

Output

Output the total number of unique entries in the contact book.

Examples